1. Field of the Invention
This invention relates to a shield to be mounted around a hot pipe to shield other components in the vicinity of the pipe from heat radiation.
2. Description of the Related Art
High performance engines used in modern vehicles tend to operate at a higher temperature than internal combustion engines of several years ago. As a result, the temperature of the exhaust manifold and other component parts rises to a level where the components may be "red hot". The problem this creates is that operating apparatus within the engine compartment having rubber, plastic or other non-metal components may be subjected to excessive and undesirable radiant heat from the hot body and thereby prematurely deteriorate the non-metal components. Examples of operating apparatus having non-metal components which fall into this category are alternators, starter motors, turbo chargers, and plastic storage containers for water and brake cylinder reservoirs.
There is a need to provide a heat shield or heat barrier between the hot body and the operating apparatus which is structured in a way to minimize heat build up in the operating apparatus as a result of radiant heat from the hot body.
A patent to Garcea, U.S. Pat. No. 4,022,019 discloses an exhaust system for an internal combustion engine with a heat shield as illustrated in FIG. 1. The shield comprises a corrugated stainless steel tube 6 clamped to the exhaust pipe 1 by a clamp 8. The insulating feature is the air pocket 11.
A patent to Engquist et al, U.S. Pat. No. 4,612,767 discloses a two layer heat shield around an exhaust manifold 16 which uses convection between the two layers 22, 42 to minimize heat radiation from manifold 16. Openings 52, 54 through the shield layers allow air to circulate from the outside to the spaces between the manifold and the two covering layers.
A patent to Akatsuka, U.S. Pat. No. 4,914,912 is somewhat difficult to read but what it has is a pair of metallic elements 8, 10 sandwiching therebetween an insulating layer 6 secured over the surface of an exhaust manifold 2. Note the transversely extending flanges at the edges of the insulating panel 4.
A patent to Moore, U.S. Pat. No. 5,233,832 illustrates a laminated heat shield made purely of metallic components and one is identified as aluminum.
A patent to Stratton et al, U.S. Pat. No. 4,182,122 discloses an insulated exhaust manifold where the insulation system is molded or cast to size, severed in two 56, 58 and then assembled over the pipe to be shielded. The disclosed system for mounting the two halves in place is by a wrapping 30.
What is needed is a heat shield structured to conform to the surface of a hot pipe to be shielded and the shield structured so that it is easily mounted or removed from the pipe when the need arises. Prior art described above and to the extent known provides certain heat shielding but it is difficult to use in assembly or disassembly when maintenance work is required on the manifold or whatever hot pipe is being shielded.